Addition: Add Whole Tens (3 Addends) (429)

Teaching Notes

Focus on place value and skip counting by tens. Encourage mental math strategies to solve these problems.

Vocabulary

Addend: A number that is added to another number.

Multiple of Ten: A number that can be divided by ten with no remainder.

Common Mistakes

• Forgetting to add all three addends.
• Miscalculating sums that cross 100.
• Not understanding that adding tens is similar to adding single digits.

Differentiation

Discussion Questions

• How is adding 50 + 30 + 20 similar to adding 5 + 3 + 2?
• What strategy helps you add multiples of 10 quickly in your head?
• Can you think of a real-life situation where you would need to add tens?
• If the sum is 140, what could be three multiples of ten that add up to it?

Extension Activities

• Add five whole tens.
• Use manipulatives to show tens.
• Connect to skip counting.

Parent Tip

Ask your child to add three different amounts of money in tens.

Skill Cluster

Number Sense & Place Value

Estimated Time

15 minutes

Skills Practiced

Prerequisites

• Adding Multiples of Ten (2 Addends)
• Counting by Tens
• Place Value to 100

Next Steps

• Adding Multiples of Hundred (3 Addends)
• Adding Two-Digit Numbers (3 Addends)
• Addition: Add Whole Tens (4 Addends)
• Addition: Add Whole Hundreds (3 Addends)
• Mental Math: Add Tens and Ones